It is proposed to establish a Laboratory Core in order to support the research activities of the University of Southern California Comprehensive Sickle Cell Center (USC CSCC). This proposed Laboratory Core represents a consolidation of three ongoing activities of the present USC CSCC: 1) Biorheology-BiophysicsCore [H.J. Meiselman, PI]; 2) Diagnostic Laboratory [C.S. Johnson, Director]; 3) Haplotype Laboratory [A.L. Hiti, Director]. The specific aims of the Laboratory Core include: 1) For Project 1 (Dr. T. Fisher, PI), to provide relevant RBC rheologic and morpholgic data as aids in defining relations between blood group polymorphismsand specific markers of disease severity; 2) For Project 2 (Dr. C. Johnson, PI), to provide relevant RBC morphologic and rheologic data, specific ELISA assays, and RBC FACS analyses in support of studies exploring pulmonary hypertension; 3) For Project 3 (Dr. T. Coates, PI), to provide rheologic/morphologic data, biophysical techniques, and specialized hematological measurements in support of studies examining hypoxia-flow relations; 4) For Project 4 (Dr. P. Malik, PI), to provide hematological and rheological analyses for mouse and human RBC, hemoglobin analyses, and specific FACS assays, to help characterize RBC populations; 5) For Project 5 (Dr. V. Kalra, PI), to provide biophysical and rheological techniques such as RBC density fractionation and cyclic deoxygenation to aid studies of mechanisms of alveolar damage; 6) For all investigators associated with the USC CSCC, to provide relevant laboratory consultation, and to provide reference laboratory and consultative services to the local and regional medical community. It should be noted that this Laboratory Core represents a new, integrated approach to providing biochemical, biophysical, hematological, and rheological information to Center researchers. It is thus anticipated that this Core will increases the understanding of the patho-physiological events occurring in sickle cell disease, thereby leading to improved patient care.